Gouglas D, et al. - For achieving vaccine research and development preparedness targets in a portfolio of 11 epidemic infectious diseases, the minimum cost estimates were determined in this study, accounting for vaccine pipeline constraints and uncertainty in research and development preparedness outcomes. Researchers found that development of a single epidemic infectious disease vaccine from preclinical trials through to end of phase 2a costs US$31–68 million (US$14–159 million range), assuming no risk of failure. With regard to the average cost of successfully advancing at least one epidemic infectious disease vaccine through to the end of phase 2a, variation from US$84–112 million ($23 million–$295 million range) starting from phase 2 to $319–469 million ($137 million–$1·1 billion range) starting from preclinical could be seen, accounting for probability of success. The cumulative cost of failed vaccine candidates through the research and development process was also included in this cost. This analysis highlights both funding needs and research and development gaps for achieving vaccine research and development preparedness targets.